Battery heating circuits and methods with resonance components in series using energy transfer and voltage inversion

ABSTRACT

According to certain embodiments, a battery heating circuit, comprising a switch unit  1 , a switching control module  100 , a damping component R 1 , an energy storage circuit, and an energy superposition and transfer unit, wherein: the energy storage circuit is connected with the battery and comprises a current storage component L 1  and a charge storage component C 1 ; the damping component R 1 , the switch unit  1 , the current storage component L 1 , and the charge storage component C 1  are connected in series; the switching control module  100  is connected with the switch unit  1  and is configured to control ON/OFF of the switch unit  1 , so as to control the energy flowing between the battery and the energy storage circuit; the energy superposition and transfer unit is connected with the energy storage circuit.

1. CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No.201010245288.0, filed Jul. 30, 2010, Chinese Patent Application No.201010274785.3, filed Aug. 30, 2010, and Chinese Patent Application No.201010606082.6, filed Dec. 23, 2010, all these three applications beingincorporated by reference herein for all purposes.

Additionally, this application is related to International ApplicationPublication No. WO2010/145439A1 and Chinese Application Publication No.CN102055042A, both these two applications being incorporated byreference herein for all purposes.

2. BACKGROUND OF THE INVENTION

The present invention pertains to electric and electronic field, inparticular related to a battery heating circuit.

Considering cars need to run under complex road conditions andenvironmental conditions or some electronic devices are used under harshenvironmental conditions, the battery, which serves as the power supplyunit for electric-motor cars or electronic devices, need to be adaptiveto these complex conditions. In addition, besides these conditions, theservice life and charge/discharge cycle performance of the battery needto be taken into consideration; especially, when electric-motor cars orelectronic devices are used in low temperature environments, the batteryneeds to have outstanding low-temperature charge/discharge performanceand higher input/output power performance.

Usually, under low temperature conditions, the resistance of the batterywill increase, and so will the polarization; therefore, the capacity ofthe battery will be reduced.

To keep the capacity of the battery and improve the charge/dischargeperformance of the battery under low temperature conditions, someembodiments of the present invention provide a battery heating circuit.

3. BRIEF SUMMARY OF THE INVENTION

The objective of certain embodiments of the present invention is toprovide a battery heating circuit, in order to solve the problem ofdecreased capacity of the battery caused by increased resistance andpolarization of the battery under low temperature conditions.

According to one embodiment, the present invention provides a batteryheating circuit, comprising a switch unit, a switching control module, adamping component R1, an energy storage circuit, and an energysuperposition and transfer unit, wherein: the energy storage circuit isconnected with the battery and comprises a current storage component L1and a charge storage component C1; the damping component R1, the switchunit, the current storage component L1, and the charge storage componentC1 are connected in series; the switching control module is connectedwith the switch unit, and is configured to control ON/OFF of the switchunit, so as to control the energy flowing between the battery and theenergy storage circuit; the energy superposition and transfer unit isconnected with the energy storage circuit, and is configured to transferthe energy in the energy storage circuit to an energy storage componentafter the switch unit switches on and then switches off, and thensuperpose the remaining energy in the energy storage circuit with theenergy in the battery.

According to one embodiment, the heating circuit provided in the presentinvention can improve the charge/discharge performance of the battery;in addition, for example, since the energy storage circuit is connectedwith the battery in series in the heating circuit, safety problem causedby failure and short circuit of the switch unit can be avoided when thebattery is heated due to the existence of the charge storage componentconnected in series, and therefore the battery can be protectedeffectively. Moreover, in another example, in the heating circuitprovided in the present invention, since the energy superposition andtransfer unit can transfer the energy in the energy storage circuit toan energy storage component after the switch unit switches off, and thensuperpose the remaining energy in the energy storage circuit with theenergy in the battery, the working efficiency of the heating circuit canbe improved and energy recycling can be achieved.

Other characteristics and advantages of the present invention will befurther described in detail in the following section for embodiments.

4. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, as a part of this description, are providedhere to facilitate further understanding of the present invention, andare used in conjunction with the following embodiments to explain thepresent invention, but shall not be comprehended as constituting anylimitation on the present invention. In the figures:

FIG. 1 is a schematic diagram showing a battery heating circuitaccording to one embodiment of the present invention;

FIG. 2 is a schematic diagram showing the energy superposition andtransfer unit as part of the battery heating circuit as shown in FIG. 1according to one embodiment of the present invention;

FIG. 3 is a schematic diagram showing the DC-DC module for the energysuperposition and transfer unit as part of the battery heating circuitas shown in FIG. 2 according to one embodiment of the present invention;

FIG. 4 is a schematic diagram showing the energy superposition andtransfer unit as part of the battery heating circuit as shown in FIG. 1according to another embodiment of the present invention;

FIG. 5 is a schematic diagram showing the electricity recharge unit aspart of the energy superposition and transfer unit for the batteryheating circuit as shown in FIG. 4 according to one embodiment of thepresent invention;

FIG. 6 is a schematic diagram showing the polarity inversion unit aspart of the energy superposition and transfer unit for the batteryheating circuit as shown in FIG. 4 according to one embodiment of thepresent invention;

FIG. 7 is a schematic diagram showing the polarity inversion unit aspart of the energy superposition and transfer unit for the batteryheating circuit as shown in FIG. 4 according to another embodiment ofthe present invention;

FIG. 8 is a schematic diagram showing the polarity inversion unit aspart of the energy superposition and transfer unit for the batteryheating circuit as shown in FIG. 4 according to yet another embodimentof the present invention;

FIG. 9 is a schematic diagram showing the DC-DC module as part of theenergy superposition and transfer unit for the battery heating circuitas shown in FIG. 8 according to one embodiment of the present invention;

FIG. 10 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to one embodimentof the present invention;

FIG. 11 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to anotherembodiment of the present invention;

FIG. 12 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention;

FIG. 13 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention;

FIG. 14 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention;

FIG. 15 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention;

FIG. 16 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention;

FIG. 17 is a schematic diagram showing the switch unit as part of thebattery heating circuit as shown in FIG. 1 according to yet anotherembodiment of the present invention;

FIG. 18 is a schematic diagram showing a battery heating circuitaccording to another embodiment of the present invention;

FIG. 19 is a schematic diagram showing the energy consumption unit aspart of the battery heating circuit as shown in FIG. 18 according to oneembodiment of the present invention;

FIG. 20 is a schematic diagram showing a battery heating circuitaccording to another embodiment of the present invention;

FIG. 21 is a timing diagram of waveforms of the battery heating circuitas shown in FIG. 20 according to one embodiment of the presentinvention;

FIG. 22 is a schematic diagram showing a battery heating circuitaccording to yet another embodiment of the present invention;

FIG. 23 is a timing diagram of waveforms of the battery heating circuitas shown in FIG. 22 according to one embodiment of the presentinvention.

5. DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the present invention are described in detailbelow, with reference to the accompanying drawings. It should beappreciated that the embodiments described here are only provided todescribe and explain the present invention, but shall not be deemed asconstituting any limitation on the present invention.

It is noted that, unless otherwise specified, when mentioned hereafterin this description, the term “switching control module” may refer toany controller that can output control commands (e.g., pulse waveforms)under preset conditions or at preset times and thereby control theswitch unit connected to it to switch on or switch off accordingly,according to some embodiments. For example, the switching control modulecan be a PLC. Unless otherwise specified, when mentioned hereafter inthis description, the term “switch” may refer to a switch that enablesON/OFF control by using electrical signals or enables ON/OFF control onthe basis of the characteristics of the component according to certainembodiments. For example, the switch can be either a one-way switch(e.g., a switch composed of a two-way switch and a diode connected inseries, which can be conductive in one direction) or a two-way switch(e.g., a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) oran IGBT with an anti-parallel freewheeling diode). Unless otherwisespecified, when mentioned hereafter in this description, the term“two-way switch” may refer to a switch that can be conductive in twodirections, which can enable ON/OFF control by using electrical signalsor enable ON/OFF control on the basis of the characteristics of thecomponent according to some embodiments. For example, the two-way switchcan be a MOSFET or an IGBT with an anti-parallel freewheeling diode.Unless otherwise specified, when mentioned hereafter in thisdescription, the term “one-way semiconductor component” may refer to asemiconductor component that can be conductive in one direction, such asa diode, according to certain embodiments. Unless otherwise specified,when mentioned hereafter in this description, the term “charge storagecomponent” may refer to any device that can enable charge storage, suchas a capacitor, according to some embodiments. Unless otherwisespecified, when mentioned hereafter in this description, the term“current storage component” may refer to any device that can storecurrent, such as an inductor, according to certain embodiments. Unlessotherwise specified, when mentioned hereafter in this description, theterm “forward direction” may refer to the direction in which the energyflows from the battery to the energy storage circuit, and the term“reverse direction” may refer to the direction in which the energy flowsfrom the energy storage circuit to the battery, according to someembodiments. Unless otherwise specified, when mentioned hereafter inthis description, the term “battery” may comprise primary battery (e.g.,dry battery or alkaline battery, etc.) and secondary battery (e.g.,lithium-ion battery, nickel-cadmium battery, nickel-hydrogen battery, orlead-acid battery, etc.), according to certain embodiments. Unlessotherwise specified, when mentioned hereafter in this description, theterm “damping component” may refer to any device that inhibits currentflow and thereby enables energy consumption, such as a resistor, etc.,according to some embodiments. Unless otherwise specified, whenmentioned hereafter in this description, the term “main loop” may referto a loop composed of battery, damping component, switch unit and energystorage circuit connected in series according to certain embodiments.

It should be noted specially that, considering different types ofbatteries have different characteristics, in some embodiments of thepresent invention, “battery” may refer to an ideal battery that does nothave internal parasitic resistance and parasitic inductance or has verylow internal parasitic resistance and parasitic inductance, or may referto a battery pack that has internal parasitic resistance and parasiticinductance; therefore, those skilled in the art should appreciate thatif the battery is an ideal battery that does not have internal parasiticresistance and parasitic inductance or has very low internal parasiticresistance and parasitic inductance, the damping component R1 may referto a damping component external to the battery and the current storagecomponent L1 may refer to a current storage component external to thebattery; if the battery is a battery pack that has internal parasiticresistance and parasitic inductance, the damping component R1 may referto a damping component external to the battery or refer to the parasiticresistance in the battery pack, and the current storage component L1 mayrefer to a current storage component external to the battery or refer tothe parasitic inductance in the battery pack, according to certainembodiments.

To ensure the normal service life of the battery, according to someembodiments, the battery can be heated under low temperature condition,which is to say, when the heating condition is met, the heating circuitis controlled to start heating for the battery; when the heating stopcondition is met, the heating circuit is controlled to stop heating,according to certain embodiments.

In the actual application of battery, the battery heating condition andheating stop condition can be set according to the actual ambientconditions, to ensure normal charge/discharge performance of thebattery, according to some embodiments.

According to one embodiment, to heat up a battery E in low temperatureenvironment, as shown in FIG. 1, the present invention provides abattery heating circuit, comprising a switch unit 1, a switching controlmodule 100, a damping component R1, an energy storage circuit, and anenergy superposition and transfer unit, wherein: the energy storagecircuit is connected with the battery, and comprises a current storagecomponent L1 and a charge storage component C1; the damping componentR1, switch unit 1, current storage component L1, and charge storagecomponent C1 are connected in series; the switching control module 100is connected with the switch unit 1, and is configured to control ON/OFFof the switch unit 1, so as to control the energy flowing between thebattery and the energy storage circuit; the energy superposition andtransfer unit is connected with the energy storage circuit, and isconfigured to transfer the energy in the energy storage circuit to anenergy storage component after the switch unit 1 switches on and thenswitches off, and then superpose the remaining energy in the energystorage circuit with the energy in the battery.

With the technical solution of certain embodiments of the presentinvention, when the heating condition is met, the switching controlmodule 100 controls the switch unit 1 to switch on, and thus the batteryE is connected with the energy storage circuit in series to form a loop,and can discharge through the loop (i.e., charge the charge storagecomponent C1); when the current in the loop reaches zero in forwarddirection after the peak current, the charge storage component C1 beginsto discharge through the loop, i.e., charge the battery E; in thecharge/discharge process of the battery E, the current in the loopalways passes through the damping component R1, no matter whether thecurrent flows in forward direction or reverse direction, and thus thebattery E is heated up by the heat generated in the damping componentR1; by controlling the ON/OFF time of the switch unit 1, the battery Ecan be controlled to heat up only in discharge mode or in both dischargemode and charge mode. When the heating stop condition is met, theswitching control module 100 can control the switch unit 1 to switch offand thereby stop the operation of the heating circuit.

The energy superposition and transfer unit is connected with the energystorage circuit, and is configured to transfer the energy in the energystorage circuit to an energy storage component after the switch unit 1switches on and then switches off, and then superpose the remainingenergy in the energy storage circuit with the energy in the battery E.Through energy transfer, energy recycling is achieved, and throughenergy superposition, the discharging current in the heating loop willbe increased when the switch unit 1 switches on again, and thereby theworking efficiency of the heating circuit can be improved.

The purpose of energy transfer is to recycle the energy in the storagecircuit, and the energy storage component can be an external capacitor,a low temperature battery or electric network, or any other electricdevices. In order to further improve the working efficiency of theheating circuit, preferably, the energy storage component is the batteryE provided in some embodiments of the present invention; thus, bytransferring the energy in the energy storage circuit to the battery E,the transferred energy can be utilized cyclically after the switch unit1 switches on again, according to certain embodiments.

The superposition of remaining energy in the energy storage circuit withthe energy in the battery E can be implemented in a variety of ways, forexample, it can be implemented by inverting the voltage polarity of thecharge storage component C1, and after polarity inversion, the voltageacross the charge storage component C1 can be added to the voltage ofthe battery E serially.

Therefore, according to one embodiment of the present invention, asshown in FIG. 2, in the heating circuit provided, the energysuperposition and transfer unit comprises a DC-DC module 4, which isconnected with the charge storage component C1 and the battery Erespectively; the switching control module 100 is also connected withthe DC-DC module 4, and is configured to transfer the energy in thecharge storage component C1 to an energy storage component bycontrolling the operation of the DC-DC module 4, and then superpose theremaining energy in the charge storage component C1 with the energy inthe battery E. In that embodiment, the energy storage component is thebattery E.

The DC-DC module 4 is a DC-DC (direct current to direct current)conversion circuit for energy transfer and voltage polarity inversioncommonly used in the field. The present invention does not impose anylimitation to the specific circuit structure of the DC-DC module 4, aslong as the module can accomplish energy transfer from the chargestorage component C1 and voltage polarity inversion of the chargestorage component C1, according to some embodiments. Those skilled inthe art can add, substitute, or delete the components in the circuit asneeded.

In one embodiment of the DC-DC module 4, as shown in FIG. 3, the DC-DCmodule 4 comprises: a two-way switch S1, a two-way switch S2, a two-wayswitch S3, a two-way switch S4, a two-way switch S5, a two-way switchS6, a fourth transformer T4, a one-way semiconductor component D13, aone-way semiconductor component D14, a current storage component L4, andfour one-way semiconductor components. In that embodiment, the two-wayswitch S1, two-way switch S2, two-way switch S3, and two-way switch S4are MOSFETs, while the two-way switch S5 and two-way switch S6 areIGBTs.

Wherein: the pin 1 and pin 3 of the fourth transformer T3 are dottedterminals; the negative electrodes of two one-way semiconductorcomponents among the four one-way semiconductor components are connectedinto a group and their junction point is connected with the positivepole of the battery E through the current storage component L4; thepositive electrodes of the other two one-way semiconductor componentsare connected into a group and their junction point is connected withthe negative pole of the battery E; in addition, the junction pointsbetween the groups are connected with pin 3 and pin 4 of the thirdtransformer T3 via two-way switch S5 and two-way switch S6 respectively,and thereby form a bridge rectifier circuit.

Wherein: the source electrode of the two-way switch S1 is connected withthe drain electrode of the two-way switch S3, the source electrode ofthe two-way switch S2 is connected with the drain electrode of thetwo-way switch S4, the drain electrodes of the two-way switch S1 andtwo-way switch S2 are connected with the positive end of the chargestorage component C1 via the one-way semiconductor component D13, thesource electrodes of the two-way switch S3 and two-way switch S4 areconnected with the negative end of the charge storage component C1 viathe one-way semiconductor component D14; thus, a full-bridge circuit isformed.

In the full-bridge circuit, the two-way switch S1 and two-way switch S2constitute the upper bridge arm, and the two-way switch S3 and two-wayswitch S4 constitute the lower bridge arm; the pin 1 of the fourthtransformer T4 is connected with the node between two-way switch S1 andtwo-way switch S3, and the pin 2 of the fourth transformer T4 isconnected with the node between two-way switch S2 and two-way switch S4.

Wherein: the two-way switch S1, two-way switch S2, two-way switch S3,and two-way switch S4, two-way switch S5, and two-way switch S6 arecontrolled by the switching control module 100 respectively to switch onand switch off.

Hereafter the working process of the DC-DC module 4 will be described:

1. After the switch unit 1 switches off, when electricity recharging isto be performed from the charge storage component C1 (i.e., transferringthe energy from the charge storage component C1 back to the battery E)so as to accomplish energy transfer, the switching control module 100controls the two-way switch S5 and S6 to switch on, and controls thetwo-way switch S1 and two-way switch S4 to switch on at the same time,to constitute phase A; the switching control module 100 controls thetwo-way switch S2 and two-way switch S3 to switch on at the same time,to constitute phase B. Thus, by controlling the phase A and phase B toswitch on alternately, a full-bridge circuit is formed;

2. When the full-bridge circuit operates, the energy in charge storagecomponent C1 is transferred to the battery E through the fourthtransformer T4 and rectifier circuit; the rectifier circuit converts theAC input into DC and outputs the DC to the battery E, to attain thepurpose of electricity recharging;

3. When polarity inversion of the charge storage component C1 is to beperformed to accomplish energy superposition, the switching controlmodule 100 controls the two-way switch S5 and two-way switch S6 toswitch off, and controls either of the two groups (two-way switch S1 andtwo-way switch S4, or two-way switch S2 and two-way switch S3) to switchon; now, the energy in the charge storage component C1 flows through thepositive end of charge storage component C1, two-way switch 51, primaryside of the fourth transformer T4, and two-way switch S4 back to thenegative end of the charge storage component C1, or flows through thepositive end of charge storage component C1, two-way switch S2, primaryside of the fourth transformer T4, and two-way switch S3 back to thenegative end of the charge storage component C1. Thus, the purpose ofvoltage polarity inversion of charge storage component C1 is attained byusing the magnetizing inductance at the primary side of T4.

In another embodiment, in the heating circuit provided in the presentinvention, the energy superposition and transfer unit can comprise anenergy superposition unit and an energy transfer unit, wherein: theenergy transfer unit is connected with the energy storage circuit, andis configured to transfer the energy in the energy storage circuit to anenergy storage component after the switch unit 1 switches on and thenswitches off; the energy superposition unit is connected with the energystorage circuit, and is configured to superpose the remaining energy inthe energy storage circuit with the energy in the battery E after theenergy transfer unit performs energy transfer.

In order to further improve the working efficiency of the heatingcircuit, preferably, the energy storage component is the battery Eprovided in some embodiments of the present invention, the energytransfer unit comprises an electricity recharge unit 103, which isconnected with the energy storage circuit, and is configured to transferthe energy in the energy storage circuit to the battery E after theswitch unit 1 switches on and then switches off, and thereby accomplishrecycling of the transferred energy, as shown in FIG. 4, according tocertain embodiments.

The superposition of the remaining energy in the energy storage circuitwith the energy in the battery E can be implemented in a variety ofways, for example, it can be implemented by inverting the voltagepolarity of the charge storage component C1. In one embodiment, as shownin FIG. 4, the energy superposition unit comprises a polarity inversionunit 102, which is connected with the energy storage circuit, and isconfigured to invert the voltage polarity of the charge storagecomponent C1 after the energy transfer unit performs energy transfer.

Hereafter the working process of the electricity recharge unit 103 andpolarity inversion unit 102 will be described in embodiments.

In one embodiment of the electricity recharge unit 103, as shown in FIG.5, the electricity recharge unit 103 comprises a second DC-DC module 3,which is connected with the charge storage component C1 and the batteryE respectively; the switching control module 100 is also connected withthe second DC-DC module 3, and is configured to control the operation ofthe second DC-DC module 3, so as to transfer the energy in the chargestorage component C1 to the battery E.

The second DC-DC module 3 is a DC-DC (direct current to direct current)conversion circuit for energy transfer commonly used in the field. Thepresent invention does not impose any limitation to the specific circuitstructure of the second DC-DC module 3, as long as the module cantransfer the energy in the charge storage component C1, according tosome embodiments. Those skilled in the art can add, substitute, ordelete the components in the circuit as needed.

FIG. 5 shows one embodiment of the second DC-DC module 3 provided in thepresent invention. As shown in FIG. 5, the second DC-DC module 3comprises: a two-way switch S1, a two-way switch S2, a two-way switchS3, a two-way switch S4, a third transformer T3, a current storagecomponent L4, and four one-way semiconductor components. In theembodiment, the two-way switch S1, two-way switch S2, two-way switch S3,and two-way switch S4 are MOSFETs.

Wherein: the pin 1 and pin 3 of the third transformer T3 are dottedterminals; the negative electrodes of two one-way semiconductorcomponents among the four one-way semiconductor components are connectedinto a group and their junction point is connected with the positivepole of the battery E through the current storage component L4; thepositive electrodes of the other two one-way semiconductor componentsare connected into a group and their junction point is connected withthe negative pole of the battery E; in addition, the junction pointsbetween the groups are connected with pin 3 and pin 4 of the thirdtransformer T3 respectively, and thereby form a bridge rectifiercircuit.

Wherein: the source electrode of the two-way switch S1 is connected withthe drain electrode of the two-way switch S3, the source electrode ofthe two-way switch S2 is connected with the drain electrode of thetwo-way switch S4, the drain electrodes of the two-way switch S1 andtwo-way switch S2 are connected with the positive end of the chargestorage component C1 respectively, the source electrodes of the two-wayswitch S3 and two-way switch S4 are connected with the negative end ofthe charge storage component C1 respectively; thus, a full-bridgecircuit is formed.

In the full-bridge circuit, the two-way switch S1 and two-way switch S2constitute the upper bridge arm, and the two-way switch S3 and two-wayswitch S4 constitute the lower bridge arm; the pin 1 of the thirdtransformer T3 is connected with the node between two-way switch S1 andtwo-way switch S3, and the pin 2 of the third transformer T3 isconnected with the node between two-way switch S2 and two-way switch S4.

Wherein: the two-way switch S1, two-way switch S2, two-way switch S3,and two-way switch S4 are controlled by the switching control module 100respectively to switch on and switch off.

Hereafter the working process of the second DC-DC module 3 will bedescribed:

1. After the switch unit 1 switches off, the switching control module100 controls the two-way switch S1 and two-way switch S4 to switch on atthe same time to form phase A; and controls the two-way switch S2 andtwo-way switch S3 to switch on at the same time to form phase B. Thus,by controlling the phase A and phase B to switch on alternately, afull-bridge circuit is formed;

2. When the full-bridge circuit operates, the energy in charge storagecomponent C1 is transferred to the battery E through the thirdtransformer T3 and rectifier circuit; and the rectifier circuit convertsthe AC input into DC and outputs the DC to the battery E, to attain thepurpose of electricity recharge.

As one embodiment of the polarity inversion unit 102, as shown in FIG.6, the polarity inversion unit 102 comprises a single-pole double-throwswitch J1 and a single-pole double-throw switch J2 located on the twoends of the charge storage component C1 respectively; the input wires ofthe single-pole double-throw switch J1 are connected in the energystorage circuit, the first output wire of the single-pole double-throwswitch J1 is connected with the first pole plate of the charge storagecomponent C1, and the second output wire of the single-pole double-throwswitch J1 is connected with the second pole plate of the charge storagecomponent C1; the input wires of the single-pole double-throw switch J2are connected in the energy storage circuit, the first output wire ofthe single-pole double-throw switch J2 is connected with the second poleplate of the charge storage component C1, and the second output wire ofthe single-pole double-throw switch J2 is connected with the first poleplate of the charge storage component C1; the switching control module100 is also connected with the single-pole double-throw switch J1 andsingle-pole double-throw switch J2 respectively, and is configured toinvert the voltage polarity of the charge storage component C1 byaltering the connection relationships between the respective input wiresand output wires of the single-pole double-throw switch J1 and thesingle-pole double-throw switch J2.

According to this embodiment, the connection relationships between therespective input wires and output wires of the single-pole double-throwswitch J1 and the single-pole double-throw switch J2 can be set inadvance, so that the input wire of the single-pole double-throw switchJ1 is connected to the first output wire of the single-pole double-throwswitch J1 and the input wire of the single-pole double-throw switch J2is connected to the first output wire of the single-pole double-throwswitch J2 when the switch unit K1 switches on; the input wire of thesingle-pole double-throw switch J1 is switched to connect with thesecond output wire of the single-pole double-throw switch J1 and theinput wire of the single-pole double-throw switch J2 is switched toconnect with the second output wire of the single-pole double-throwswitch J2 under control of the switching control module 100 when theswitch unit K1 switches off, and thereby the voltage polarity of thecharge storage component C1 is inverted.

As another embodiment of the polarity inversion unit 102, as shown inFIG. 7, the polarity inversion unit 102 comprises a one-waysemiconductor component D3, a current storage component L2, and a switchK9; the charge storage component C1, current storage component L2, andswitch K9 are connected sequentially in series to form a loop; theone-way semiconductor component D3 is connected in series between thecharge storage component C1 and the current storage component L2 orbetween the current storage component L2 and the switch K9; theswitching control module 100 is also connected with the switch K9, andis configured to invert the voltage polarity of the charge storagecomponent C1 by controlling the switch K9 to switch on.

According to the above embodiment, when the switch unit 1 switches off,the switch K9 can be controlled to switch on by the switching controlmodule 100, and thereby the charge storage component C1, one-waysemiconductor component D3, current storage component L2, and switch K9form a LC oscillation loop, and the charge storage component C1discharges through the current storage component L2, thus, the voltagepolarity of the charge storage component C1 will be inverted when thecurrent flowing through the current storage component L2 reaches zeroafter the current in the oscillation circuit flows through the positivehalf cycle.

As yet another embodiment of the polarity inversion unit 102, as shownin FIG. 8, the polarity inversion unit 102 comprises a first DC-DCmodule 2 and a charge storage component C2; the first DC-DC module 2 isconnected with the charge storage component C1 and the charge storagecomponent C2 respectively; the switching control module 100 is alsoconnected with the first DC-DC module 2, and is configured to transferthe energy in the charge storage component C1 to the charge storagecomponent C2 by controlling the operation of the first DC-DC module 2,and then transfer the energy in the charge storage component C2 back tothe charge storage component C1, so as to invert the voltage polarity ofthe charge storage component C1.

The first DC-DC module 2 is a DC-DC direct current to direct current)conversion circuit for voltage polarity inversion commonly used in thefield. The present invention does not impose any limitation to thespecific circuit structure of the first DC-DC module 2, as long as themodule can accomplish voltage polarity inversion of the charge storagecomponent C1, according to some embodiments. Those skilled in the artcan add, substitute, or delete the components in the circuit as needed.

FIG. 9 shows one embodiment of the first DC-DC module 2 provided in thepresent invention. As shown in FIG. 9, the first DC-DC module 2comprises: a two-way switch Q1, a two-way switch Q2, a two-way switchQ3, a two-way switch Q4, a first transformer T1, a one-way semiconductorcomponent D4, a one-way semiconductor component D5, a current storagecomponent L3, a two-way switch Q5, a two-way switch Q6, a secondtransformer T2, a one-way semiconductor component D6, a one-waysemiconductor component D7, and a one-way semiconductor component D8.

In the embodiment, the two-way switch Q1, two-way switch Q2, two-wayswitch Q3, and two-way switch Q4 are MOSFETs, and the two-way switch Q5and two-way switch Q6 are IGBTs.

The Pin 1, 4, and 5 of the first transformer T1 are dotted terminals,and the pin 2 and 3 of the second transformer T2 are dotted terminals.

Wherein: the positive electrode of the one-way semiconductor componentD7 is connected with the end ‘a’ of the charge storage component C1, andthe negative electrode of the one-way semiconductor component D7 isconnected with the drain electrodes of the two-way switch Q1 and two-wayswitch Q2, respectively; the source electrode of the two-way switch Q1is connected with the drain electrode of the two-way switch Q3, and thesource electrode of the two-way switch Q2 is connected with the drainelectrode of the two-way switch Q4; the source electrodes of the two-wayswitch Q3 and two-way switch Q4 are connected with the end ‘b’ of thecharge storage component C1 respectively. Thus, a full-bridge circuit isformed, here, the voltage polarity of end ‘a’ of the charge storagecomponent C1 is positive, while the voltage polarity of end ‘b’ of thecharge storage component C1 is negative.

In the full-bridge circuit, the two-way switch Q1, two-way switch Q2constitute the upper bridge arm, while the two-way switch Q3 and two-wayswitch Q4 constitute the lower bridge arm. The full-bridge circuit isconnected with the charge storage component C2 via the first transformerT1; the pin 1 of the first transformer T1 is connected with the firstnode N1, the pin 2 of the first transformer T1 is connected with thesecond node N2, the pin 3 and pin 5 of the first transformer T1 areconnected to the positive electrode of the one-way semiconductorcomponent D4 and the positive electrode of the one-way semiconductorcomponent D5 respectively; the negative electrode of one-waysemiconductor component D4 and the negative electrode of one-waysemiconductor component D5 are connected with one end of the currentstorage component L3, and the other end of the current storage componentL3 is connected with the end ‘d’ of the charge storage component C2; thepin 4 of the transformer T1 is connected with the end ‘c’ of the chargestorage component C2, the positive electrode of the one-waysemiconductor component D8 is connected with the end ‘d’ of the chargestorage component C2, and the negative electrode of the one-waysemiconductor component D8 is connected with the end ‘b’ of the chargestorage component C1; here, the voltage polarity of end ‘c’ of thecharge storage component C2 is negative, while the voltage polarity ofend ‘d’ of the charge storage component C2 is positive.

Wherein: the end ‘c’ of the charge storage component C2 is connectedwith the emitter electrode of the two-way switch Q5, the collectorelectrode of the two-way switch Q5 is connected with the pin 2 of thetransformer T2, the pin 1 of the transformer T2 is connected with end‘a’ of the charge storage component C1, the pin 4 of the transformer T2is connected with end ‘a’ of the charge storage component C1, the pin 3of the transformer T2 is connected with the positive electrode of theone-way semiconductor component D6, the negative electrode of theone-way semiconductor component D6 is connected with the collectorelectrode of the two-way switch Q6, and the emitter electrode of thetwo-way switch Q6 is connected with the end ‘b’ of the charge storagecomponent C2.

Wherein: the two-way switch Q1, two-way switch Q2, two-way switch Q3,two-way switch Q4, two-way switch Q5, and two-way switch Q6 arecontrolled by the switching control module 100 respectively to switch onand switch off.

Hereafter the working process of the first DC-DC module 2 will bedescribed:

1. After the switch unit 1 switches off, the switching control module100 controls the two-way switch Q5 and two-way switch Q6 to switch off,and controls the two-way switch Q1 and two-way switch Q4 to switch on atthe same time to form phase A; controls the two-way switch Q2 andtwo-way switch Q3 to switch on at the same time to form phase B. Thus,by controlling the phase A and phase B to switch on alternately, afull-bridge circuit is formed;

2. When the full-bridge circuit operates, the energy in the chargestorage component C1 is transferred through the first transformer T1,one-way semiconductor component D4, one-way semiconductor component D5,and current storage component L3 to the charge storage component C2;now, the voltage polarity of end ‘c’ of the charge storage component C2is negative, while the voltage polarity of end ‘d’ of the charge storagecomponent C2 is positive.

3. The switching control module 100 controls the two-way switch Q5 toswitch on, and therefore a path from the charge storage component C1 tothe charge storage component C2 is formed via the second transformer T2and the one-way semiconductor component D8, thus, the energy in thecharge storage component C2 is transferred back to the charge storagecomponent C1, wherein: some energy will be stored in the secondtransformer T2, Now, the switching control module 100 controls thetwo-way switch Q5 to switch off and controls the two-way switch Q6 toswitch on, and therefore the energy stored in the second transformer T2is transferred to the charge storage component C1 by the secondtransformer T2 and the one-way semiconductor component D6; now, thevoltage polarity of the charge storage component C1 is inverted suchthat end ‘a’ is negative and end is positive. Thus, the purpose ofinverting the voltage polarity of the charge storage component C1 isattained.

To prevent the charge storage component C1 from charging the battery Eat low temperature and ensure the charge/discharge performance of thebattery E, in one embodiment of the heating circuit provided in thepresent invention, the switching control module 100 is configured tocontrol ON/OFF of the switch unit 1, so as to control the energy to flowfrom the battery E to the energy storage circuit only, and thus thecharging of battery E by the charge storage component C1 is prevented.

In order to control the energy to flow from the battery E to the chargestorage component C1 only, in one embodiment of the present invention,as shown in FIG. 10, the switch unit 1 comprises a switch K1 and aone-way semiconductor component D1, wherein: the switch K1 and theone-way semiconductor component D1 are connected with each other inseries, and then connected in series in the energy storage circuit; theswitching control module 100 is connected with the switch K1, and isconfigured to control ON/OFF of the switch unit 1 by controlling ON/OFFof the switch K1. By connecting a one-way semiconductor component D1 inseries in the circuit, energy backflow from the charge storage componentC1 can be prevented, and thereby charging of battery E can be avoided incase the switch K1 fails.

As for the embodiment in which the energy flows from the battery E tothe charge storage component C1 only, the switching control module 100is configured to control the switch unit 1 to switch off when or beforethe current flow through the switch unit 1 reaches zero after the switchunit 1 switches on, as long as the current is controlled to flow fromthe battery E to the charge storage component C1 only.

Since the current drop rate is very high when the switch K1 switchesoff, high over-voltage will be induced on the current storage componentL1 and may cause damage to the switch K1 because the current and voltageare beyond the safe working range. Therefore, preferably the switchingcontrol module 100 is configured to control the switch K1 to switch offwhen the current flow through the switch unit 1 reaches zero after theswitch unit 1 switches on.

To improve heating efficiency, preferably, in another embodiment of thepresent invention, as shown in FIG. 11, the switching control module 100is configured to control the switch unit 1 to switch off before thecurrent flow through the switch unit 1 reaches zero after the switchunit 1 switches on; the switch unit 1 comprises a one-way semiconductorcomponent D9, a one-way semiconductor component D10, a switch K2, adamping component R4, and a charge storage component C3, wherein: theone-way semiconductor component D9 and the switch K2 are connected inseries in the energy storage circuit, the damping component R4 and thecharge storage component C3 are connected in series, and then connectedin parallel across the switch K2; the one-way semiconductor componentD10 is connected in parallel across the damping component R4, and isconfigured to sustain the current to the current storage component L1when the switch K2 switches off; the switching control module 100 isconnected with the switch K2, and is configured to control ON/OFF of theswitch unit 1 by controlling ON/OFF of the switch K2.

The one-way semiconductor component D10, damping component R4, andcharge storage component C3 constitute an absorption loop, which isconfigured to reduce the current drop rate in the energy storage circuitwhen the switch K2 switches off. Thus, when the switch K2 switches off,the induced voltage generated on the current storage component L1 willforce the one-way semiconductor component D10 to switch on and enablescurrent freewheeling with the charge storage component C3, so as toreduce the current change rate in the current storage component L1 andto suppress the induced voltage across the current storage component L1,to ensure the voltage across the switch K2 is within the safe workingrange. When the switch K2 switches on again, the energy stored in thecharge storage component C3 can be consumed through the dampingcomponent R4.

In order to improve the working efficiency of the heating circuit, theenergy can be controlled to flow back-and-forth between the battery Eand the energy storage circuit, so as to utilize current flow throughthe damping component R1 in both forward direction and reverse directionto enable heating.

Therefore, in one embodiment of the heating circuit provided in thepresent invention, the switching control module 100 is configured tocontrol ON/OFF of the switch unit 1, so that the energy flowsback-and-forth between the battery E and the energy storage circuit whenthe switch unit 1 is in ON state.

To enable energy flow to-and-fro between the battery E and the energystorage circuit, in one embodiment of the present invention, the switchunit 1 is a two-way switch K3; as shown in FIG. 12, the switchingcontrol module 100 controls ON/OFF of the two-way switch K3, i.e., whenthe battery E needs to be heated, the two-way switch K3 can becontrolled to switch on, when heating is to be paused or is not needed,the two-way switch K3 can be controlled to switch off.

Employing a separate two-way switch K3 to implement the switch unit 1can simplify the circuit, reduce system footprint, and facilitate theimplementation; however, to implement cut-off of reverse current, thefollowing embodiment of the switch unit 1 is further provided in thepresent invention.

Preferably, the switch unit 1 comprises a first one-way branchconfigured to enable energy flow from the battery E to the energystorage circuit, and a second one-way branch configured to enable energyflow from the energy storage circuit to the battery E; wherein: theswitching control module 100 is connected to either or both of the firstone-way branch and second one-way branch, to control ON/OFF of theconnected branches.

When the battery needs to be heated, both the first one-way branch andthe second one-way branch can be controlled to switch on; when heatingneeds to be paused, either or both of the first one-way branch and thesecond one-way branch can be controlled to switch off; when heating isnot needed, both of the first one-way branch and the second one-waybranch can be controlled to switch off. Preferably, both of the firstone-way branch and the second one-way branch are subject to the controlof the switching control module 100; thus, energy flow cut-off inforward direction and reverse direction can be implemented flexibly.

In another embodiment of the switch unit 1, as shown in FIG. 13, theswitch unit 1 may comprise a two-way switch K4 and a two-way switch K5,wherein: the two-way switch K4 and the two-way switch K5 are connectedin series opposite to each other, to form the first one-way branch andthe second one-way branch; the switching control module 100 is connectedwith the two-way switch K4 and the two-way switch K5 respectively, tocontrol ON/OFF of the first one-way branch and the second one-way branchby controlling ON/OFF of the two-way switch K4 and two-way switch K5.

When the battery E needs to be heated, the two-way switches K4 and K5can be controlled to switch on; when heating needs to be paused, eitheror both of the two-way switch K4 and the two-way switch K5 can becontrolled to switch off; when heating is not needed, both of thetwo-way switch K4 and the two-way switch K5 can be controlled to switchoff. In such an implementation of switch unit 1, the first one-waybranch and the second one-way branch can be controlled separately toswitch on or off, and therefore energy flow cut-off in forward directionand reverse direction in the circuit can be implemented flexibly.

In another embodiment of switch unit 1, as shown in FIG. 14, the switchunit 1 may comprise a switch K6, a one-way semiconductor component D11,and a one-way semiconductor component D12, wherein: the switch K6 andthe one-way semiconductor component D11 are connected in series witheach other to form the first one-way branch; the one-way semiconductorcomponent D12 forms the second one-way branch; the switching controlmodule 100 is connected with the switch K6, to control ON/OFF of thefirst one-way branch by controlling ON/OFF of the switch K6. In theswitch unit 1 shown in FIG. 14, when heating is needed, the switch K6can be controlled to switch on; when heating is not needed, the switchK6 can be controlled to switch off.

Though the implementation of switch unit 1 shown in FIG. 14 enablesto-and-fro energy flow along separate branches, it cannot enable energyflow cut-off function in reverse direction. The present inventionfurther puts forward another embodiment of switch unit 1; as shown inFIG. 15, the switch unit 1 can further comprise a switch K7 in thesecond one-way branch, wherein: the switch K7 is connected with theone-way semiconductor component D12 in series, the switching controlmodule 100 is also connected with the switch K7, and is configured tocontrol ON/OFF of the second one-way branch by controlling ON/OFF of theswitch K7. Thus, in the switch unit 1 shown in FIG. 15, since there areswitches (i.e., switch K6 and switch K7) in both one-way branches,energy flow cut-off function in forward direction and reverse directionis enabled simultaneously.

Preferably, the switch unit 1 can further comprise a resistor, which isconnected in series with the first one-way branch and/or the secondone-way branch and is configured to reduce the current in the heatingcircuit for the battery E and to avoid damage to the battery E resultedfrom over-current in the circuit. For example, a resistor R6 connectedin series with the two-way switch K4 and the two-way switch K5 can beadded in the switch unit 1 shown in FIG. 13, to obtain anotherimplementation of the switch unit 1, as shown in FIG. 16. FIG. 17 alsoshows one embodiment of the switch unit 1, which is obtained byconnecting respectively resistor R2 and resistor R3 in series in boththe one-way branches in the switch unit 1 shown in FIG. 15.

In one embodiment in which the energy flows back-and-forth between thebattery E and the energy storage circuit, the switch unit 1 can becontrolled to switch off at any point of time in one or more cycles,which is to say, the switch unit 1 can switch off at any time, forexample, the switch unit 1 can switch off when the current flows throughthe switch unit 1 in forward direction or reverse direction, and isequal to zero or not equal to zero. A specific implementation form ofthe switch unit 1 can be selected, depending on the needed cut-offstrategy; if current flow cut-off in forward direction is only needed,the implementation form of the switch unit 1 shown in FIG. 12 or FIG. 14can be selected; if current flow cut-off in both forward direction andreverse direction is needed, the switch unit with two controllableone-way branches shown in FIG. 13 or FIG. 15 can be selected.

Preferably, the switching control module 100 is configured to controlthe switch unit 1 to switch off when or after the current flow throughthe switch unit 1 reaches zero after the switch unit 1 switches on. Morepreferably, the switching control module 100 is configured to controlthe switch unit 1 to switch off when the current flow through the switchunit 1 reaches zero after the switch unit 1 switches on, so as tominimize the adverse effect to the entire circuit.

In one embodiment of the present invention, the working efficiency ofthe heating circuit can be improved by transferring and superposing theenergy in the charge storage component C1, or transferring andsuperposing the remaining energy in the charge storage component C1after some energy in the charge storage component C1 is consumed.

Thus, as shown in FIG. 18, the heating circuit further comprises anenergy consumption unit, which is connected with the charge storagecomponent C1 and configured to consume the energy in the charge storagecomponent C1 after the switch unit 1 switches on and then switches off.The energy consumption unit can be combined with the embodimentsdescribed above, including the embodiments in which the energy flowsfrom the battery to the energy storage circuit only, and the embodimentsin which the energy flows back-and-forth between the battery and theenergy storage circuit.

In one embodiment, as shown in FIG. 19, the energy consumption unitcomprises a voltage control unit 101, which is connected with the chargestorage component C1, and is configured to convert the voltage valueacross the charge storage component C1 to the predetermined value ofvoltage after the switch unit 1 switches on and then switches off andbefore the energy superposition and transfer unit performs energytransfer, or convert the voltage value across the charge storagecomponent C1 to the predetermined value of voltage after the energysuperposition and transfer unit performs energy transfer and before theenergy superposition and transfer unit performs energy superposition.The sequence of consumption, transfer and superposition of energy in thecharge storage component C1 can be set as needed, and is not limitedaccording to certain embodiments of the present invention. Thepredetermined value of voltage can be set as needed.

In one embodiment of the present invention, as shown in FIG. 19, thevoltage control unit 101 comprises a damping component R5 and a switchK8, wherein: the damping component R5 and switch K8 are connected witheach other in series, and then connected in parallel across the chargestorage component C1; the switching control module 100 is also connectedwith the switch K8, and is configured to control the switch K8 to switchon after the switch unit 1 switches on and then switches off. Thus, theenergy in the charge storage component C1 can be consumed across thedamping component R5.

The switching control module 100 can be a separate controller, which, byusing internal program setting, enables ON/OFF control of differentexternal switches; or, the switching control module 100 can be aplurality of controllers, for example, a switching control module 100can be set for each external switch correspondingly; or, the pluralityof switching control modules 100 can be integrated into an assembly. Thepresent invention does not impose any limitation on implementation ofthe switching control module 100, according to some embodiments.

The working process of certain embodiments of the heating circuit forbattery E is described briefly below with reference to FIGS. 20-23.

It should be noted that though the features and components of someembodiments of the present invention are described specifically withreference to FIGS. 20-23, each feature or component may be usedseparately without other features and components, or may be used incombination or not in combination with other features and components.The embodiments of the heating circuit for battery E provided are notlimited to those shown in FIGS. 20-23. In addition, the grid part of thewaveforms indicates that drive pulses can be applied to the switch oneor more times within the period, and the pulse width can be adjusted asneeded according to some embodiments.

For example, in the heating circuit for battery E as shown in FIG. 20, aswitch K1 and a one-way semiconductor component D1 constitute the switchunit 1; the energy storage circuit comprises a current storage componentL1 and a charge storage component C1; the damping component R1 and theswitch unit 1 are connected in series with the energy storage circuit;the DC-DC module 4 constitutes an energy superposition and transfer unitthat transfers the energy in the charge storage component C1 back to thebattery E and then invert the voltage polarity of the charge storagecomponent C1 so as to superpose the energy with the energy in thebattery E in the next charge/discharge cycle; the switching controlmodule 100 can control ON/OFF of the switch K1 and the operation of theDC-DC module 4. FIG. 21 is a timing diagram of waveforms correspondingto the heating circuit as shown in FIG. 20, wherein: V_(C1) refers thevoltage value across the charge storage component C1, and I_(main)refers to the value of current flowing through the switch K1. In anotherexample, the working process of the heating circuit as shown in FIG. 20is as follows:

a) When the battery E is to be heated, the switching control module 100controls the switch K1 to switch on, and thereby the battery Edischarges through the loop composed of the switch K1, the one-waysemiconductor component D1, and the charge storage component C1, asindicated by the time duration t1 as shown in FIG. 21; when the currentflowing through the switch K1 is zero, the switching control module 100controls the switch K1 to switch off, as indicated by the time durationt2 as shown in FIG. 21;

b) After the switch K1 switches off, the switching control module 100controls the DC-DC module 4 to start to operate; the charge storagecomponent C1 converts some AC current into DC current and outputs the DCcurrent to the battery E via the DC-DC module 4, and thereby accomplishelectricity recharging, as indicated by the time duration t2 as shown inFIG. 21;

c) The switching control module 100 controls the DC-DC module 4 to startto operate, to invert the voltage polarity of the charge storagecomponent C1; then, it controls the DC-DC module 4 to stop operating, asindicated by the time duration t3 as shown in FIG. 21;

d) Repeat step a) through step c); the battery E is heated upcontinuously while it discharges, till the battery E meets the heatingstop condition.

For example, in the heating circuit for battery E as shown in FIG. 22, aswitch K6 and a one-way semiconductor component D11 are connected toeach other in series (the first one-way branch) and a switch K7 and aone-way semiconductor component D12 are connected to each other inseries (the second one-way branch) to constitute the switch unit 1; theenergy storage circuit comprises a current storage component L1 and acharge storage component C1; the damping component R1 and the switchunit 1 are connected in series with the energy storage circuit; theDC-DC module 4 constitutes an energy superposition and transfer unitthat transfers the energy in the charge storage component C1 back to thebattery E and then inverts the voltage polarity of the charge storagecomponent C1 so as to superpose the energy with the energy in battery Ein the next charge/discharge cycle; the switching control module 100 cancontrol ON/OFF of the switch K6 and the switch K7 and the operation ofthe DC-DC module 4. FIG. 23 is a timing diagram of waveformscorresponding to the heating circuit as shown in FIG. 22, wherein:V_(C1) refers to the voltage value across the charge storage componentC1, and I_(main) refers to the value of current flowing through theswitch K1. In another example, the working process of the heatingcircuit as shown in FIG. 22 is as follows:

a) The switching control module 100 controls the switch K6 and theswitch K7 to switch on, and therefore the energy storage circuit startsto operate, as indicated by the time duration t1 as shown in FIG. 23;the battery E discharges in forward direction through the switch K6, theone-way semiconductor component D11, and the charge storage component C1(as indicated by the time duration t1 as shown in FIG. 23), and ischarged in reverse direction through the charge storage component C1,the switch K7, and the one-way semiconductor D12 (as indicated by thetime duration t2 as shown in FIG. 23);

b) The switching control module 100 controls the switch K6 and theswitch K7 to switch off when the current in reverse direction is zero;

c) The switching control module 100 controls the DC-DC module 4 to startto operate; the charge storage component C1 converts the AC current intoDC current and outputs the DC current to the battery E via the DC-DCmodule 4, to accomplish electricity recharging; then, the DC-DC module 4inverts the voltage polarity of the charge storage component C1; afterpolarity inversion of C1, the switching control module 100 controls theDC-DC module 4 to stop operating, as indicated by the time durations t3and t4 shown in FIG. 23;

d) Repeat step a) through step c); the battery E is heated upcontinuously while it discharges, till the battery E meets the heatingstop condition.

According to one embodiment, the heating circuit provided in the presentinvention can improve the charge/discharge performance of the battery;in addition, for example, since the energy storage circuit is connectedwith the battery in series in the heating circuit, safety problem causedby failure and short circuit of the switch unit can be avoided when thebattery is heated due to the existence of the charge storage componentconnected in series, and therefore the battery can be protectedeffectively. Moreover, in another example, in the heating circuitprovided in the present invention, since the energy superposition andtransfer unit can transfer the energy in the energy storage circuit toan energy storage component after the switch unit switches off, and thensuperpose the remaining energy in the energy storage circuit with theenergy in the battery, the working efficiency of the heating circuit canbe improved, and energy recycling can be achieved.

According to one embodiment, a battery heating circuit, comprising aswitch unit 1, a switching control module 100, a damping component R1,an energy storage circuit, and an energy superposition and transferunit, wherein: the energy storage circuit is connected with the batteryand comprises a current storage component L1 and a charge storagecomponent C1; the damping component R1, the switch unit 1, the currentstorage component L1, and the charge storage component C1 are connectedin series; the switching control module 100 is connected with the switchunit 1, and is configured to control ON/OFF of the switch unit 1, so asto control the energy flowing between the battery and the energy storagecircuit; the energy superposition and transfer unit is connected withthe energy storage circuit, and is configured to transfer the energy inthe energy storage circuit to an energy storage component after theswitch unit 1 switches on and then switches off, and then superpose theremaining energy in the energy storage circuit with the energy in thebattery.

For example, wherein: the damping component R1 is the parasiticresistance in the battery, and the current storage component L1 is theparasitic inductance in the battery. In another example, wherein: thedamping component R1 is a resistor, the current storage component L1 isan inductor, and the charge storage component C1 is a capacitor. In yetanother example, wherein: the energy superposition and transfer unitcomprises a DC-DC module 4, which is connected with the charge storagecomponent C1 and the battery respectively; the switching control module100 is also connected with the DC-DC module 4, and is configured tocontrol the operation of the DC-DC module 4 to transfer the energy inthe charge storage component C1 to the energy storage component, andthen superpose the remaining energy in the charge storage component C1with the energy in the battery.

In yet another example, wherein: the energy superposition and transferunit comprises an energy superposition unit and an energy transfer unit;the energy transfer unit is connected with the energy storage circuitand is configured to transfer the energy in the energy storage circuitto an energy storage component after the switch unit 1 switches on andthen switches off; the energy superposition unit is connected with theenergy storage circuit and is configured to superpose the remainingenergy in the energy storage circuit with the energy in the batteryafter the energy transfer unit performs energy transfer.

In yet another example, wherein: the energy storage component is thebattery, and the energy transfer unit comprises an electricity rechargeunit 103, which is connected with the energy storage circuit and isconfigured to transfer the energy in the energy storage circuit to thebattery after the switch unit 1 switches on and then switches off. Inyet another example, wherein: the electricity recharge unit 103comprises a second DC-DC module 3, which is connected with the chargestorage component C1 and the battery respectively; the switching controlmodule 100 is also connected with the second DC-DC module 3 and isconfigured to transfer the energy in the charge storage component C1 tothe battery by controlling the operation of the second DC-DC module 3.In yet another example, wherein: the energy superposition unit comprisesa polarity inversion unit 102, which is connected with the energystorage circuit and is configured to invert the voltage polarity of thecharge storage component C1 after the energy transfer unit performsenergy transfer.

In yet another example, wherein: the polarity inversion unit 102comprises a single-pole double-throw switch J1 and a single-poledouble-throw switch J2 located on the two ends of the charge storagecomponent C1 respectively; the input wire of the single-poledouble-throw switch 31 is connected within the energy storage circuit,the first output wire of the single-pole double-throw switch 31 isconnected with the first pole plate of the charge storage component C1,and the second output wire of the single-pole double-throw switch J1 isconnected with the second pole plate of the charge storage component C1;the input wire of the single-pole double-throw switch J2 is connectedwithin the energy storage circuit, the first output wire of thesingle-pole double-throw switch J2 is connected with the second poleplate of the charge storage component C1, and the second output wire ofthe single-pole double-throw switch J2 is connected with the first poleplate of the charge storage component C1; the switching control module100 is also connected with the single-pole double-throw switch J1 andthe single-pole double-throw switch J2 respectively and is configured toinvert the voltage polarity of the charge storage component C1 byaltering the connection relationships between the respective input wiresand output wires of the single-pole double-throw switch J1 and thesingle-pole double-throw switch J2. In yet another example, wherein: thepolarity inversion unit 102 comprises a one-way semiconductor componentD3, a current storage component L2, and a switch K9; the charge storagecomponent C1, the current storage component L2, and the switch K9 areconnected sequentially in series to form a loop; the one-waysemiconductor component D3 is connected in series between the chargestorage component C1 and the current storage component L2 or between thecurrent storage component L2 and the switch K9; the switching controlmodule 100 is also connected with the switch K9 and is configured toinvert the voltage polarity of the charge storage component C1 bycontrolling the switch K9 to switch on. In yet another example, wherein:the polarity inversion unit 102 comprises a first DC-DC module 2 and acharge storage component C2; the first DC-DC module 2 is connected withthe charge storage component C1 and the charge storage component C2respectively; the switching control module 100 is also connected withthe first DC-DC module 2 and is configured to transfer the energy in thecharge storage component C1 to the charge storage component C2 bycontrolling the operation of the first DC-DC module 2, and then transferthe energy in the charge storage component C2 back to the charge storagecomponent C1, so as to invert the voltage polarity of the charge storagecomponent C1.

In yet another example, wherein: the switching control module 100 isconfigured to control ON/OFF of the switch unit 1, so as to control theenergy to flow from the battery to the energy storage circuit only. Inyet another example, wherein: the switch unit 1 comprises a switch K1and a one-way semiconductor component D1; the switch K1 and the one-waysemiconductor component D1 are connected with each other in series, andthen connected within the energy storage circuit in series; theswitching control module 100 is connected with the switch K1 andconfigured to control ON/OFF of the switch unit 1 by controlling ON/OFFof the switch K1. In yet another example, wherein: the switching controlmodule 100 is configured to control the switch unit 1 to switch off whenor before the current flow through the switch unit 1 reaches zero afterthe switch unit 1 switches on. In yet another example, wherein: theswitching control module 100 is configured to control the switch unit 1to switch off before the current flowing through the switch unit 1reaches zero after the switch unit 1 switches on; the switch unit 1comprises a one-way semiconductor component D9, a one-way semiconductorcomponent D10, a switch K2, a resistor R4, and a charge storagecomponent C3; the one-way semiconductor component D9 and the switch K2are connected in series within the energy storage circuit; the resistorR4 and the charge storage component C3 are connected with each other inseries and then connected across the switch K2 in parallel; the one-waysemiconductor component D10 is connected in parallel across the dampingcomponent R4 and is configured to sustain the current flowing throughthe current storage component L1 when the switch K2 switches off; theswitching control module 100 is connected with the switch K2 and isconfigured to control ON/OFF of the switch unit 1 by controlling ON/OFFof the switch K2.

In yet another example, wherein: the switching control module 100 isconfigured to control ON/OFF of the switch unit 1, so that the energyflows back-and-forth between the battery and the energy storage circuitwhen the switch unit 1 switches on. In yet another example, wherein: theswitch unit 1 is a two-way switch K3. In yet another example, wherein:the switch unit 1 comprises a first one-way branch configured to enableenergy flow from the battery to the energy storage circuit and a secondone-way branch configured to enable energy flow from the energy storagecircuit to the battery; the switching control module 100 is connected toeither or both of the first one-way branch and the second one-waybranch, and is configured to control ON/OFF of the switch unit 1 bycontrolling ON/OFF of the connected branch(es). In yet another example,wherein: the switch unit 1 comprises a two-way switch K4 and a two-wayswitch K5; the two-way switch K4 and the two-way switch K5 are connectedin series opposite to each other to form the first one-way branch andthe second one-way branch; the switching control module 100 is connectedwith the two-way switch K4 and the two-way switch K5 respectively, andis configured to control ON/OFF of the first one-way branch and thesecond one-way branch by controlling ON/OFF of the two-way switch K4 andthe two-way switch K5.

In yet another example, wherein: the switch unit 1 comprises a switchK6, a one-way semiconductor component D11, and a one-way semiconductorcomponent D12; the switch K6 and the one-way semiconductor component D11are connected with each other in series to constitute the first one-waybranch; the one-way semiconductor component D12 constitutes the secondone-way branch; the switching control module 100 is connected with theswitch K6 and is configured to control ON/OFF of the first one-waybranch by controlling ON/OFF of the switch K6. In yet another example,wherein: the switch unit 1 further comprises a switch K7 in the secondone-way branch, and the switch K7 is connected with the one-waysemiconductor component D12 in series; the switching control module 100is further connected with the switch K7 and is configured to controlON/OFF of the second one-way branch by controlling ON/OFF of the switchK7. In yet another example, wherein: the switch unit 1 further comprisesa resistor connected in series with the first one-way branch and/or thesecond one-way branch.

In yet another example, wherein: the switching control module 100 isconfigured to control the switch unit 1 to switch off when or after thecurrent flowing through the switch unit 1 reaches zero after the switchunit 1 switches on. In yet another example, wherein: the heating circuitfurther comprises an energy consumption unit, which is connected withthe charge storage component C1, and is configured to consume the energyin the charge storage component C1 after the switch unit 1 switches onand then switches off and before the energy superposition and transferunit performs energy transfer, or to consume the energy in the chargestorage component C1 after the energy superposition and transfer unitperforms energy transfer and before the energy superposition andtransfer unit performs energy superposition.

In yet another example, wherein: the energy consumption unit comprises avoltage control unit 101, which is connected with the charge storagecomponent C1 and is configured to convert the voltage value across thecharge storage component C1 to the predetermined voltage value after theswitch unit 1 switches on and then switches off and before the energysuperposition and transfer unit performs energy transfer, or to convertthe voltage value across the charge storage component C1 to thepredetermined voltage value after the energy superposition and transferunit performs energy transfer and before the energy superposition andtransfer unit performs energy superposition. In yet another example,wherein: the voltage control unit 101 comprises a damping component R5and a switch K8; the damping component R5 and the switch K8 areconnected in series with each other, and then connected in parallelbetween the two ends of the charge storage component C1; the switchingcontrol module 100 is also connected with the switch K8 and is alsoconfigured to control the switch K8 to switch on after controlling theswitch unit 1 to switch on and then to switch off.

According to certain embodiments, a battery heating circuit, comprisinga switch unit 1, a switching control module 100, a damping component R1,an energy storage circuit, and an energy superposition and transferunit, wherein: the energy storage circuit is connected with the batteryand comprises a current storage component L1 and a charge storagecomponent C1; the damping component R1, the switch unit 1, the currentstorage component L1, and the charge storage component C1 are connectedin series; the switching control module 100 is connected with the switchunit 1 and is configured to control ON/OFF of the switch unit 1, so asto control the energy flowing between the battery and the energy storagecircuit; the energy superposition and transfer unit is connected withthe energy storage circuit, and is configured to transfer the energy inthe energy storage circuit to an energy storage component after theswitch unit 1 switches on and then switches off, and then superpose theremaining energy in the energy storage circuit with the energy in thebattery. For example, the heating circuit provided in the presentinvention can improve the charge/discharge performance of a battery,enhance the safety of battery heating, and improve the workingefficiency of the heating circuit. In another example, energy recyclingcan be achieved.

For example, some or all components of various embodiments of thepresent invention each are, individually and/or in combination with atleast another component, implemented using one or more softwarecomponents, one or more hardware components, and/or one or morecombinations of software and hardware components. In another example,some or all components of various embodiments of the present inventioneach are, individually and/or in combination with at least anothercomponent, implemented in one or more circuits, such as one or moreanalog circuits and/or one or more digital circuits.

While some embodiments of the present invention are described above withreference to the accompanying drawings, the present invention is notlimited to the details of those embodiments. Those skilled in the artcan make modifications and variations, without departing from the spiritof the present invention. However, all these modifications andvariations shall be deemed as falling into the scope of the presentinvention.

In addition, it should be noted that the specific technical featuresdescribed in the above embodiments can be combined in any appropriateway, provided that there is no conflict. To avoid unnecessaryrepetition, certain possible combinations are not describedspecifically. Moreover, the different embodiments of the presentinvention can be combined as needed, as long as the combinations do notdeviate from the spirit of the present invention. However, suchcombinations shall also be deemed as falling into the scope of thepresent invention.

Hence, although specific embodiments of the present invention have beendescribed, it will be understood by those of skill in the art that thereare other embodiments that are equivalent to the described embodiments.Accordingly, it is to be understood that the invention is not to belimited by the specific illustrated embodiments, but only by the scopeof the appended claims.

1. A circuit for heating a battery, the circuit comprising: the batteryincluding a first damping component and a first current storagecomponent, the first damping component and the first current storagecomponent being parasitic to the battery; a switch unit; a switchingcontrol component coupled to the switch unit; a first charge storagecomponent, the first charge storage component and the first currentstorage component being at least parts of an energy storage circuit; andan energy transfer and superposition unit coupled to the first chargestorage component; wherein: the first damping component, the firstcurrent storage component, the switch unit, and the first charge storagecomponent are connected in series; the switching control component isconfigured to turn on and off the switch unit so as to control a currentflowing between the battery and the first charge storage component; andthe energy transfer and superposition unit is configured to, after theswitch unit is turned on and then turned off, transfer first energy fromthe first charge storage component to an energy storage component andthen adjust a storage voltage associated with the first charge storagecomponent so that a positive voltage terminal of the first chargestorage component is coupled, directly or indirectly, to a negativevoltage terminal of the battery; wherein the circuit for heating thebattery is configured to heat the battery by at least discharging thebattery.
 2. The circuit of claim 1 wherein: the first damping componentis a parasitic resistor of the battery; and the first current storagecomponent is a parasitic inductor of the battery.
 3. The circuit ofclaim 2 wherein the first charge storage component is a capacitor. 4.The circuit of claim 1 wherein: the energy storage component includesthe battery; the energy transfer and superposition unit includes a DC-DCmodule coupled to the first charge storage component and the battery;and the switching control component is coupled to the DC-DC module andconfigured to control the DC-DC module to transfer the first energy fromthe first charge storage component to the battery and then adjust thestorage voltage associated with the first charge storage component sothat the positive voltage terminal of the first charge storage componentis coupled, directly or indirectly, to the negative voltage terminal ofthe battery.
 5. The circuit of claim 1 wherein: the energy transfer andsuperposition unit includes an energy transfer unit and an energysuperposition unit; the energy transfer unit is coupled to the firstcharge storage component and configured to, after the switch unit isturned on and then turned off, transfer the first energy from the firstcharge storage component to the energy storage component; and the energysuperposition unit is coupled to the first charge storage component andconfigured to adjust the storage voltage associated with the firstcharge storage component so that the positive voltage terminal of thefirst charge storage component is coupled, directly or indirectly, tothe negative voltage terminal of the battery.
 6. The circuit of claim 5wherein: the energy storage component includes the battery; and theenergy transfer unit includes an electricity recharge unit coupled tothe battery and configured to transfer the first energy from the firstcharge storage component to the battery after the switch unit is turnedon and then turned off.
 7. The circuit of claim 6 wherein: theelectricity recharge unit includes a DC-DC module coupled to the firstcharge storage component and the battery; and the switching controlcomponent is coupled to the DC-DC module and configured to control theDC-DC module to transfer the first energy from the first charge storagecomponent to the battery.
 8. The circuit of claim 5 wherein the energysuperposition unit includes a polarity inversion unit coupled to thefirst charge storage component and configured to, after the switch unitis turned on and then turned off, invert a voltage polarity associatedwith the first charge storage component.
 9. The circuit of claim 8wherein the polarity inversion unit includes: a first single-poledouble-throw switch coupled to a first storage terminal of the firstcharge storage component; and a second single-pole double-throw switchcoupled to a second storage terminal of the second charge storagecomponent; wherein: the first single-pole double-throw switch includes afirst input wire, a first output wire, and a second output wire; thefirst input wire is coupled, directly or indirectly, to the firstbattery terminal; and the first output wire and the second output wireare coupled to the first storage terminal and the second storageterminal respectively; wherein: the second single-pole double-throwswitch includes a second input wire, a third output wire, and a fourthoutput wire; the second input wire is coupled, directly or indirectly,to the second battery terminal; and the third output wire and the fourthoutput wire are coupled to the second storage terminal and the firststorage terminal respectively; wherein the switching control componentis coupled to the first single-pole double-throw switch and the secondsingle-pole double-throw switch, and is configured to invert the voltagepolarity associated with the first charge storage component by alteringconnection relationships among the first input wire, the first outputwire, the second output wire, the second input wire, the third outputwire, and the fourth output wire.
 10. The circuit of claim 8 wherein thepolarity inversion unit includes: a second current storage component; asecond switch; and a first one-way semiconductor component connectedbetween the first charge storage component and the second currentstorage component or between the second current storage component andthe second switch; wherein: the first charge storage component, thefirst one-way semiconductor component, the current storage component,and the second switch are at least parts of a polarity inversion loop;and the switching control component is coupled to the second switch andis configured to invert the voltage polarity associated with the firstcharge storage component by turning on the second switch.
 11. Thecircuit of claim 8 wherein the polarity inversion unit includes: asecond charge storage component; and a first DC-DC module coupled to thesecond charge storage component and the first charge storage component;wherein the switching control component is coupled to the first DC-DCmodule and configured to invert the voltage polarity associated with thefirst charge storage component by transferring energy from the firstcharge storage component to the second charge storage component and thentransferring the energy from the second charge storage component back tothe first charge storage component.
 12. The circuit of claim 1 whereinthe switch unit and the switching control component are configured toallow the current to flow from the battery to the first charge storagecomponent if the switch unit is turned on, but never allow the currentto flow from the first charge storage component to the battery.
 13. Thecircuit of claim 12 wherein: the switch unit includes a first switch anda first one-way semiconductor component connected in series with thefirst switch; and the switching control component is coupled to thefirst switch and configured to turn on and off the switch unit byturning on and off the first switch respectively.
 14. The circuit ofclaim 12 wherein the switching control component is configured to, afterthe switch unit is turned on, turn off the switch unit when or beforethe current reduces to zero in magnitude.
 15. The circuit of claim 14wherein the switch unit includes: a first one-way semiconductorcomponent; a second one-way semiconductor component; a first switch; asecond damping component connected in parallel with the second one-waysemiconductor component; and a second charge storage component connectedin series with a combination of the second damping component and thesecond one-way semiconductor component; wherein: the first switch isconnected in parallel with a combination of the second dampingcomponent, the second one-way semiconductor component, and the secondcharge storage component; and the first one-way semiconductor componentis connected in series with a combination of the first switch, thesecond damping component, the second one-way semiconductor component,and the second charge storage component; wherein the switching controlcomponent is coupled to the first switch and configured to turn off theswitch unit by turning off the first switch before the current reducesto zero in magnitude.
 16. The circuit of claim 1 wherein the switchingcontrol component is configured to turn on the switch unit and allow thecurrent to flow from the battery to the first charge storage componentand to flow from the first charge storage component to the battery. 17.The circuit of claim 16 wherein the switch unit includes a two-wayswitch.
 18. The circuit of claim 16 wherein the switch unit includes afirst branch circuit for conduction in a first direction and a secondbranch circuit for conduction in a second direction, the first directionbeing from the battery to the first charge storage component, the seconddirection being from the first charge storage component to the battery.19. The circuit of claim 18 wherein the switching control component iscoupled to the first branch circuit and configured to turn on and offthe first branch circuit.
 20. The circuit of claim 18 wherein theswitching control component is coupled to the first branch circuit andthe second branch circuit and configured to turn on and off the firstbranch circuit and the second branch circuit respectively.
 21. Thecircuit of claim 18 wherein: the first branch circuit includes a firstswitch and a first one-way semiconductor component connected in serieswith the first switch, the first switch being coupled to the switchcontrol component; and the second branch circuit includes a secondone-way semiconductor component; wherein the switching control componentis further configured to turn on and off the first branch circuit byturning on and off the first switch respectively.
 22. The circuit ofclaim 21 wherein: the second branch circuit further includes a secondswitch coupled to the switching control component and connected inseries with the second one-way semiconductor component; wherein theswitching control component is further configured to turn on and off thesecond branch circuit by turning on and off the second switchrespectively.
 23. The circuit of claim 18 wherein the switch unitfurther includes a resistor connected in series with at least the firstbranch circuit or the second branch circuit.
 24. The circuit of claim 16wherein the switch unit includes: a first two-way switch coupled to theswitch control unit; and a second two-way switch coupled to the switchcontrol unit and connected in series with the first two-way switch;wherein the switch control unit is further configured to turn on and offthe first two-way switch and to turn on and off the second two-wayswitch.
 25. The circuit of claim 1 wherein the switching controlcomponent is configured to: turn on the switch unit to allow the currentto flow between the battery and the first charge storage component; andthen, turn off the switch unit when or after the current decreases tozero in magnitude.
 26. The circuit of claim 1 is further configured to:start heating the battery if at least one heating start condition issatisfied; and stop heating the battery if at least one heating stopcondition is satisfied.
 27. The circuit of claim 1, and furthercomprising an energy consumption unit coupled to the first chargestorage component and configured to consume second energy stored in thefirst charge storage component after the switch unit is turned on andthen turned off.
 28. The circuit of claim 27 wherein the energyconsumption unit is further configured to consume the second energystored in the first charge storage component after the switch unit isturned on and then turned off but before the energy transfer andsuperposition unit transfers the first energy from the first chargestorage component to the energy storage component.
 29. The circuit ofclaim 27 wherein the energy consumption unit is further configured toconsume the second energy stored in the first charge storage componentafter the switch unit is turned on and then turned off and after theenergy transfer and superposition unit transfers the first energy fromthe first charge storage component to the energy storage component. 30.The circuit of claim 27 wherein the energy consumption unit includes avoltage control unit configured to regulate the storage voltageassociated with the first charge storage component to a predeterminedvoltage after the switch unit is turned on and then turned off.
 31. Thecircuit of claim 30 wherein the voltage control unit includes: a seconddamping component; and a first switch connected in series with thesecond damping component; wherein the first charge storage component isconnected in parallel with a combination of the second damping componentand the first switch.